Networking vendor Cisco has billions of cash on hand and isn't afraid to use it to augment its core offerings. The latest acquisition for the networking giant is Software as a Service (SaaS) Web security vendor ScanSafe.

Cisco (NASDAQ:CSCO) is set to pay $183 million in cash for the privately held ScanSafe. The company said it expects the deal to close in the November-January timeframe.

With ScanSafe, Cisco aims to expand its Web-based security portfolio. Among ScanSafe's offerings is the Anywhere+ SaaS service that provides malware protection and policy usage enforcement on users' laptops. ScanSafe also offers Web filtering technology that includes a URL filtering database and file type filters to protect users from Web-based threats.

Once the acquisition closes, the plan is for ScanSafe's service to be integrated with Cisco's AnyConnect VPN Client to help provide a secure mobile VPN solution.

The technology will complement Cisco's existing Ironport services, which the company has recently been expanding into the SaaS realm.

In March, Cisco announced IronPort's e-mail security as both a SaaS offering and a hybrid model that merges cloud computing with an on-site presence. The IronPort technology itself also came by way of acquisition for Cisco: In 2007, the company paid $830 million for IronPort.

SaaS and cloud-based security has been a big thrust for Cisco in 2009. In April, Cisco announced a series of updates to its portfolio built around Cisco Security Cloud Services, an initiative designed to help enterprises benefit from Cisco's aggregated security information and resources in the cloud today.

The acquisition of ScanSafe is also the third major company acquisition undertaken by Cisco this month alone. On Oct. 1, Cisco announced its intention to purchase video conferencing vendor Tandberg for $3 billion, though the deal has since met with some shareholder resistance.

At the time, Cisco CEO John Chambers said that Cisco plans to be very aggressive when it comes to acquisitions, especially since it has $35 billion in cash with which to make purchases.

Two weeks after agreeing to buy Tandberg, Cisco also announced an agreement to purchase mobile networking vendor Starent for $2.9 billion.